NortH AMERICAN SPECIES OF LESKEA 473 
The characters of LZ. mucrocarpa are fairly constant, except 
the acumination of the leaves, which varies considerably. In 
Musc. Allegh. 7o. 69, taken as the type, the leaves are rather long 
and narrowly acuminate, in this respect resembling Z. nervosa ; 
but in the ordinary forms of the species they are shorter acumi- 
nate, not rarely gradually acute, sometimes even blunt-pointed or 
obtuse. ZL. microcarpa differs from L. nervosa in being monoicous, 
leaves papillose, costa rough on lower surface and exothecial cells 
roundish oblong. Its distinguishing characters are its small 
angular leaf-cells and its rough costa. 
8. LESKEA NERVOSA (Schwagr.) Myrin, Coroll. Fl. Upsal. 52. 
1834. Bry. Eur. fasc. 44 and 45 Mon. 4. p/. 3. 1850. 
Pterogonium nervosum Schwagr. Suppl. 1': 102. 1811. 
Anomodon rigidulus Kindb. Laubm. Schwed. u. Norw. II. 
1883. 
Anomodon subrigidulus Kindb. Eur. and N. Am. Bry. 11. 
1896.* 
In thin appressed tufts, pale green to dark green, older parts 
rusty brown or black; stems creeping, 4-7 cm. long, radiculose, 
not paraphyllose, pinnately branched ; branches simple, ascend- 
ing, sometimes branched ; central strand small, distinct: stem- 
leaves broadly ovate, subcordate, slightly decurrent, abruptly 
long-acuminate, 0.35—0.5 mm. wide, 0.8-1.3 mm. long; acumen 
narrowly lanceolate-linear, more or less recurved, margins plane, 
subsinuate ; body concave (subcochleariform), biplicate, margins 
sometimes recurved on one or both sides ; costa subpercurrent, 
narrow, scarcely tapering; branch-leaves narrow, rigid, erect- 
spreading, 0.2—0.3 mm. wide, 0.6-0.9 mm. long; leaf-cells smooth 
or scarcely papillose, somewhat uniform ; median cells ova]-hex- 
agonal to oval-oblong, 7-9 x 8-124; alar quadrate to trans- 
versely oval in 5 or 6 rows, extending well up the margins and 
becoming roundish: dioicous: perichetial bracts long and nar- 
rowly acuminate, inner erect, subvaginant, slightly costate ; pedi- 
cel smooth, 10-12 mm. long; capsule erect, subcylindric, 
brownish, wrinkled when dry ; urn 2.2 mm. long, 0.7 mm. wide ; 
exothecial cells oblong, several rows about mouth roundish hex- 
agonal, thick-walled ; teeth erect, confluent at base, linear-lanceo- 
late, yellowish, margined, dorsal surface finely striate, divisural 
* For a more extended synonymy of this species as well as the others of this 
Revision the reader is referrred to Limpricht’s ‘‘ Die Laubmoose’’ and Braithwaite’s 
‘* British Moss-Flora.’’ 
